When changing a fuel filter, an air pocket is often created. The air pocket may cause difficulty for an associated fuel pump drawing fuel through a fuel line from a fuel supply reservoir. Similarly, using a sump fuel pump submerged in the fuel supply reservoir might push the air pocket through the fuel line to associated fuel injectors which are not designed to function with air pockets in the fuel. Moreover, operating fuel injectors with such air pockets may damage the fuel injectors.
The earliest solution to this problem was an attempt to reduce the volume of the air pockets by as much as possible. A person performing the filter change poured clean fuel into the new fuel filter. This operation reduced the volume of the air pockets, but it could not completely eliminate the air pockets.
A similar method of removing the void is by filling the filter with fuel after installation. This usually is accomplished by manually actuating a control valve to select either a normal flow path or a priming fuel path. In the priming fuel path, fuel is siphoned through an inlet into a filter head. In the filter head a hand pump pushes fuel into the fuel filter. See U.S. Pat. No. 5,362,392 issued to Jensen Nov. 8, 1994. After filling the fuel filter, the control valve is used to select the normal flow path which bypasses the hand pump. Other similar methods employ check valves instead of manually actuating the control valve.
Manual pumps and manually actuated control valves, however, create inconveniences for both designers and operators. For example, operators may inadvertently fail to reposition the control valve to allow for fuel to flow in the normal path. Typically the designer must pay close attention to ergonomic considerations of both filter removal and pump actuation. Specifically, designers that utilize manual pumps must consider whether an operator is able to reach the manual pump and filter without getting too close to hot or dirty engine parts or work in the cramped confines of the vehicle structure.
Other related art shows an electric charge pump atop a fuel filter. See U.S. Pat. No. 5,231,967 issued to Baltz et al. Aug. 3, 1993. This integrated pump and filter is adapted for continuous use as a main fuel pump as opposed to a priming pump. Moreover, the Baltz et. al. pump/filter combination operates any time the ignition switch is on and is not selectively operable. This electric pump is exposed to vibrations associated with the vehicle operation. The present invention is directed at overcoming one or more of the problems set forth above.